Hydraulic press



pril" 7, 1925.

1,532,140 E. HUTCHENS HYDRAULIC PRESs Filed p il 2. 1924 VTTJF Edward Hutch-e I Patented'Apr. 7, 19.25;

UNITED STATES PATENT OFFICE.

EDWARD HUTCHENS, OF MILWAUKEE, WISCONSIN, FACTURING COMPANY, OF GUDAHY, WISCONSIN, A

ASSIGNOR T UTILITY MANU- CORPORATION OF WISCONSIN.

HYDRAULIC 1131185.

Application filed April 2; 1924. Serial 11 0. 703,618.

llrbeing had to the accompanying drawings,

therefore an object of and to the numerals of reference marked thereon, which form a part of this specification.

This invention relates to details of the construction of hydraulic presses, and has particular reference to the provision of a uniform maximum unit pressure over the entire working area of the press plate.

In hydraulic presses as usually constructed when the maximum pressure is exerted by the ram against the bottom of the press plate there is of course some spring in' the plate as the ram is necessarily of smaller area than the press plate, and consequently when a product is compressed between a pair of press plates it varies in thickness between the edges and center. Heretofore ithas been endeavored to overcome this defect by providing an enlarged or mushroom head for the ram to distribute the ram pressure as far out as possible on the press plate. This can not entirely eliminate the spring in the press the mushroom ram head will of course yield at its edges due to the high pressures ord 1 narily used in hydraulic press work. It is vide means compensating for the unavoidable'distortion of the ram head under maximum load to provide an equalized pressure on the first press plate whereby the press plate will not be distorted and so result in non-parallel surfaces on the work compressed between a series of such press plates.

It is also an object of this invention to provide a means for uniformly heating the press, plates for a vulcanizing press by means of a drainage system for condensed steam which prevents lodgment of the con densate in pockets resulting in uneven heat transmission to the material being vulcanized.

Other and further important objects of this invention will be apparent from the disclosures in the draw ngs and specification.

embodying t plate because P this invention to pro- This invention (in a preferred form) is illustrated on the drawings and hereinafter more fully described. On the drawings: .Figure 1 is a side elevation of a hydraulic press having a plurality of press plates,

e features of this invention.

Figure 2 is an enlarged section on the line 22 of Figure 1 showing the top of the ram head.

Figure 3 is an enlarged section on the line 33 of Figure 1 showing the construction of the ram head.

Figure 4 isan enlarged fragmentary section on the line 4-4 of Figure 3 showing means for condensate drainage.

As shown on the drawings:

A base 10 containing a hydfiulic cylinder 11 is indicated in the figures together with a suitable fluid supply pipe 12 and packing ring 13. A ram or piston 14 reciprocable in the cylinder llis shown with an enlarged or mushroom head 15 adapted to contact the bottom of the lowest of a series of press plates 16. A press top is shown at 17 tied to the base 10 by several tension rods 18- passing through suitable bosses 19 on ,the top and base and secured by nuts 20. The tension rods 18 also serve as guide for the intermediate press plates 16.

With the hydraulic press in the open po-- sition of- Figure 1 the press plates are susended at an approximate equal spacing over the stroke of the ram by rods 21 which slide through apertures in plates 22 on the press top, said rods having nuts 23 which imit the plates to provide a plurality of openings to receive the material to be operated upon. The press plates are cored out as indicated at 24 to provide steam pockets for: vulcanizing, and steam is supplied thereto through the pipes 25 which slide in cylinders 26 when the press plates move under the action of the ram. The steam outlets 27 from the press plates are so positioned as to positively drain all condensate from the steam pockets to prevent accumulation of water therein which affects the heat transference and thereby results in uneven vulcanizing with the consequent production of" s oiled work or seconds. By the elimination of waterpockets in the steam passages the percentage of spoile WOLk is greatlyreduced,

downward motion of the press I The mushroom head of the ram 14 as heretofore manufactured was flat on the top dependence being placed on bulky brackets or flanges 28 connecting the overhanging edges of the head 15 to the ram 14 proper. In this invention the head of the ram is machined slightly concave as at 29, the maximum deviation from a plane surface being signed strong enough to withstand the maximum pressure and therefore has a greatly increased margin of reserve strength and as a corollary extra stifi'ness under lighter loads. By the provision of a concave surface on the ram head the whole structure can be made lighter and therefore more cheaplyfor the same capacity, while producing greatly improved uniformity of section in the product for the reason that parts designed of ample strength are not necessarily ofample stiffness. As a matter of fact no practical design can be prepared that will not yield somewhat under the enormous loads imposed in hydraulic presses, so that the present invention provides means for overcoming an inherent defect of the earlier forms.

I am aware that numerous details of con struction may be varied through a wide range without departing from the princi-' ples of this invention, and I therefore do not purpose limiting the patent granted, otherwise than necessitated by the prior art.

I claim as my invention:

1. ha hydraulic press comprising a hydraulic cylinder and suitable press plates therefor, a ram having a working surface machined concave to normally contact the press plate around the periphery of the working surface of the ram whereby deflection of the rain surface under maximum load will produce a surface of uniform contact between the ram and the press plate.

2. In a device of the class described a hydraulic ramhaving a slightly concave working surface, Work receiving plates adapted to transmit the pressure produced by said ram, said plates being cored for a heating fluid, and means adapted to drain spent fluid from said plates to prevent uneven accumulation thereof in portions ofsaid plates.

3. In a hydraulic press, a ram head having a concave surface adapted to compensate for distortion of the material of the head under maximum ressures.

4. In a hydraulic press a ram head, and a press plate normall contacted by said head at the'periphery t ereof, said head being adapted to uniformly contact said press plate under conditions of maximum load.

In testimony whereof I have hereunto subscribed my name in the presence of two subscribmg wltnesses.

EDWARD HUTCHENS.

Witnesses: I

OARIIION HILL, OSCAR HARTMANN. 

